Economizer door for boiler enclosures



July 25; 1944. B.-LABAREE ET AL 7 2,354,334

4 ECONOMIZER DOOR FOR BOILER ENCLOSURES Filed Aug. 25, 1941 ZShGBtS-ShBGt 1 75 13ml? 22 H G Q {INVENTORS BenjaminLobaree x Robert Kkntpe.

BY M1 7 ATTORNEY B. LABAREE EFAL ECONOMIZER DOOR FOR BOILER ENCLOSURES July 25, 1944.

Filed Aug. 25, 1941 2 Shegts-Sheet 2 PICrL Patented July 25, 1944 UNITED STATES {PATENT OFFICE ECONOMIZER noon FOR BOILER ENCLOSURES Benjamin Labaree and Robert K. Knipe, Philadelphia, Pa., assignors to Edward G. Budd Man- 'Philadelphia, Pa., a corporation of Pennsylvania,

Application August 25, 1941, Serial No. 408,224

, 4 Claims. (Cl. 189-34) ufacturing Company,

' The invention refers to a door or removable panel for boiler enclosures as they are used for instance, on the steam boilers of ships. More particularly the invention refers to removable panels which are known as economizer doors.

An object of the invention is a removable panel for boiler enclosures which is strong and rigid yet lighter than the previously used ones.

Another object of the invention is a panel or door which is gas-tight itself and which can easily be gas-tightly connected to adjoining parts of the boiler enclosure.

' An object of the invention is also a panelv or door which is adapted to resist considerable pressure and which has heat insulating properties.

The aforesaid objects are especially important for boiler enclosures for ships where every pound saved in weight means a corresponding increase in payload, armament, cruising radius, etc., but where, on the otherhand, the saving of weight must not go at the expense of the strength and the durability of the structure. In naval vessels in particular, such ascruisers or destroyers saving in weight on the one hand and utmost efficiency anddurability on the other hand are both of paramount importance.

The above objects. and other. objects are achieved according to the invention by a panel or door which, is composed of a corrosion resistant alloy such as austenitic stainless steel, which comprises an outer substantially uninterrupted sheet and marginal angle or Z-shaped rails having one of .the arms attached to theinner surface of said sheet, and which comprises. furthermore, angle or Z-section cross members or stiffeners, all said members being united into one rigid and gas-tight structure by a type of electric spot welding which does not impair the desirable properties of the steel, such as corrosion resistance and the strength'attained by cold working. Yet, certain members as will be seen later on, are gas or arc welded, are of a corrosion resistancev alloy which is not deleteriously affected by prolonged heating, and are used in the annealed state.

I The details of the invention as well as further objects and advantages thereof will become apparent fromthe attached drawings illustrating an embodiment and from the following description of the latter embodiment.

In the drawings: Figure l is a diagram endelevation of an enclosed boiler.

, Figure 2 is an elevation on a larger scale of theta economizer door forming part of the enclosure shown in Figure 1; j

Figure 3' is a fragmentary section along line 3 3 of Figure 2 on a still larger scale;

Figure 4 is a fragmentary section along line 4- 1 of Figure 2 through the connections between two sections of the door on a scale larger than that of Figures 2 or 3;

Figures '5, 6 and 7 are fragmentary sections along the correspondingly'numbered lines of Figure 2 and on about the same scale as Figure 4, showing different details of the door. Figure 8 is a fragmentary view of the meeting corners of the two door sections, the view corresponding to the portion encircled by the dash and dot line 8 of Figure 2;

Figure 9 is an end view of the meeting corners of the door sections viewed in the direction of the arrows 9--9 of Figure 8;

Figure 10 is a fragmentary section similar to that of Figure 5, showing also adjoiningparts of the boiler enclosure and means for. holding the door in place.

In Figure 1 of the drawings, 20 are the water drums of the boiler which are inter-connected by banks of-not shown-tubes. The entire system of tubes inter-connecting the drums 20 and the combustion chambers between them are covered up by a double walled enclosure, the one end view of which is visible in Figure 1 and which is generally designated by numeral 2|. I

The left-hand portion 22 of the boiler enclosure shown in Figure 1 leads to the smoke stack. In this portion 22 is arranged an economizer, that is a system of tubes in which water is preheated by the combustion gases leaving the combustionchambers. 23 are supply or discharge tubes for the water circulating in the-not sho'wn-economizer tubes proper. economizer is afforded by a removable panel or door 24 consisting of two rigidly connected sections 25 and 2B.

, Each door section 25 or 26 comprisesa metal sheet 21 which is substantially flat throughout except for the outwardly directed marginal flange 21'- in the region where the two sections meet each other. Z-section rails 28, 29 and 30 have oneoi their arms 3I- fastened to the inner surface of the panel 21' along the margins. of the latter except along the margins where the two sections25 and 26 meet. The web 32 of said rails extends inwardly and the other arm 33 extends parallel to the panel 21 toward the center of the door. Along the margins where the two sections 25 and 26 meet, the panels 21 are rein- Access to the forced by angle section rails 34 having one of their arms 35 arranged on the inside of the panel 21 adjacent the flange 21', whereas the other arm 33 extends outwardly and overlaps said flange 21'. The meeting ends of the rails 28, 29 and 30 are connected to one another by butt welding, and the flanges 3| of the rails 28 and 30 are connected in the same manner to the arm 35 of the rail 34. The butt welds between adjacent flanges 3| and between the flanges 3| and flanges 35 are ground flush on both sides.

A plurality of Z-section stifieners or rails 31 are arranged parallel to and spaced from each other and the rails 28 and 34. One arm 38 underlies and is fastened by spot welding to the inner side of the panel 21. The web 39 of the rails 31 extends inwardly and the ends of the outer arm 45 overlies and is fastened to the arms 33 of the rails 28 and 33.

The panels 2'. are each provided with a hole 4| for the entrance of the water tube 23, One of the stiifeners 31 of each section 25 or 2-6 is interrupted in the region of this hole 4|. The ends of the interrupted stiffener are tied into the adjacent uninterrupted stiffeners 31 by short 2- section members 42 having again one of the arms 43 fastened to the inside of the panel 21 whereas the web 44 extends inwardly and the outer arm 45 away from the opening 4|. The arm 45 underlies and is connected to the end of the arm 40 of the adjacent interrupted rail 31. Tongues 46 are formed at the ends of the web 44 and are fastened to the webs 39 of the adjoining uninterrupted rails 31. A reinforcing. plate 41 is welded to the inner side of the panel 21 in the region of the hole 4| and is likewise provided with a registering hole.

The panel 21 is connected to the flanges 31 of the rails 28, 29 and 30 and to both armsl35 and 33 of the rail 34 by gas-tight electric seam welds. The arrangement of such seams 48 at the corner of one section are indicated in Figure. 8. It will be noted that the seams alon different sides cross each other at the corner. The seam between flange 21 of the panel 21 and arm 36 of the rail 34 is indicated at 49 in Figure l.

' The outer side of the panel 21, except for its margins, is covered by a heat insulatin plate consisting of an insulating layer such as an asbestos mill board 56 and of a light sheet metal plate having inturned margins 52. The insulating plate 53, 5| is fastened to the panel 21 by means of screws 53 and nuts 54. The nuts 54 are welded to the outer surface of the panel 21. It will be noted that the panel 21 is not pierced for the.

screws 53.

Pairs of handles 55 are connected to each of the two sections 25 and 26 of, the economizer door by means of bolts 56 and nuts 51. The shank 58 of. the bolts extends through openings in the panels 21 and 5|. The panel 21 is reinforced in the region of the bolts by an inner washer 59 and an outer washer 60. The washer 59 is spot welded at 5| to the plate 21, and in addition a seam weld 62 extends all around the washer 59 so as to make a gas-tight connection. The washer 60 is simply spot welded to the outer side of the plate 21 at 63 A gas or are weld 64 makes a gas-tight joint between the bolt 56 and the washer 59. The thickness of the Washer 6|! is equal to the thickness of the insulation board 50 which is provided in this region with a hole of corresponding size.

All the rail members, illCllldll'lg the rail 34, are bent from sheet metal and have therefore no sharp edges where their flanges or webs meet. For obtaining a gas-tight connection between the door and adjoining portions of the boiler enclo- 75 sure it is, however desirable to have a square edge at the ends of the rails 34 between the flanges 35 and 36. For this purpose-as shown in Figure 9metal 65 is deposited by gas or arc welding along the corner between the two flanges from their ends to a distance about equal to the width of theflange 3| of the rails 28 and 30. This metal 65 is then ground square.

The two sections and 26 of the door are connected by screws and bolts 66 extending through the flanges 21 and the arms 36 of rails 34, an asbestos gasket 61 being clamped between the opposite surfaces of the flanges 36 so as to give a gas-tight joint. V 7 When the door consisting of the sections 25 and 2.6 is placed in the opening of the boiler enclosure, the arms 3| of the rails 28, 29 and and the ends of the arms of the rails 34 rest on a heat resisting gasket 68, Figure 10, the latter being supported by a marginal portion 69 of the adjoining structure of the boiler enclosure. The aforesaid parts of the door being pressed against the gasket 68 by means of a plurality of clamps 13 and bolts and nuts 1| of which one only is illustrated in Figure 10., It is not necessary to describe this connection in further detail because it is a common expedient for holding man hole covers and the like.

Most of the joints between the different parts of the door are electric spot or Scam welds except where a different kind of connection is specifically described. The panel 21, the stiffeners 31 and 42 and the handles are preferably ordinary stainless austenitic, chromium-nickel steel, the strength of which has materially been increased by cold rolling. These members are connected to each other and to adjoining members by electric spot or seam welding in such a manner that their corrosion resistance and strength is not impaired. The marginal rails 28, 29, 30 and 34 which require arc or gas welding, that is a treatment which would. impair the corrosion resistance of ordinary stainless steel and. the strength of cold rolled stock, are preferably made of a stainless steel of the type which is not alfected by pro: longed heating. For these parts a low-carbon austenitic stainless steel in annealed condition may, for instance, be used. For some members such as the reinforcing plate 41, washers 59, nuts 54 and the cover sheet 5|, the most convenient and economic type of stainless steel is employable.

Doors according to the invention have been sub jected extensively to severe tests and it has been found that they live up to the expectations by performing their duties just as satisfactory or even better than the doors that were used before, although they are cheaper, simpler and quicker to manufacture and lighter in weight.

Although only one embodiment has been shown, it is obvious that the invention is liable to a great number of modifications and adaptations. The outer form, for instance, of the door and the location of the holes for the tubes will be diiferent for nearly each different type of boiler, and it is obvious that for this reason alone slight changes have to be made. Another example of possible change are the rails and stifieners, which may have other cross sections such as angle section. All such changes and variations are intended to be covered by the following claims.

What is claimedis:

1. A light weight removable sheet metal panel structure for boiler enclosures such as an economizer door; said structure comprising a substantially uninterrupted metal sheet; an angle or Z- section marginal rail having one arm gas-tightly secured. to the inner surface of the sheet, said arm extending laterally away from the center of the door and having its margin substantially coincide with a margin of said sheet; angle or Z- section cross rails or stiffeners extending across said structure and being arranged spaced from and generally parallel to each other, said cross rails having one of their arms likewise secured to the inner side of said sheet; a heat insulating plate being secured to the outside of said sheet by means attached to the uninterrupted outer side of the sheet; the margin of the sheet and the arm of said marginal rail which overlap each other being adapted to be gas-tightly clamped to the margins of an opening in the adjoining boiler enclosure structure; said panel with its marginal and cross rails being furthermore adapted to withstand considerable difference in pressure on its opposite sides without undue distortion.

2. A light weight removable sheet metal panel structure for boiler enclusures such as an economizer door; said structure comprising a substantially uninterrupted metal sheet; angle or Z-section marginal rails each having an arm gastightly secured to the inner surface of the sheet, said arm extending laterally away from the center of the door and having its margin substantially coincide with a margin of said sheet; the arms of adjoining rails which are secured to the inner surface of said sheet having their ends integrally joined with the joint therebetween flush on both sides with the sides of the arms so joined; angle or Z-section cross rails or stifieners extending across said structure and being arranged spaced from and generally parallel to each other, said cross rails having one of their arms likewise secured to the inner side of said erable difierence in pressure sheet; the margin of the sheet and said marginal rail which overlap each other being adapted to be gas-tightly clamped to the margins of an opening in the adjoining boiler enclosure structure; said panel with its marginal and cross rails being furthermore adapted to withstand considwithout undue distortion.

3. A light weight removable sheet metal panel structure for boiler enclosures such as an economizer door; said structure consisting of two sections; each section comprising a substantially uninterrupted metal sheet; angle or Z-section marginal rails having one arm gas-tightly secured to the inner surface of the sheet, said arm extending laterally away from the center of the door and having its margin substantially coincide with a margin of said panel sheet, the adjoining arm or web extending inwardly; another angle section marginal rail having one arm likewise fastened to the inner side of said sheet and integrally joined to the first-named arm of said first-named marginal rails and having its other arm extending outwardly so as to form part of the connecting means between the two sections.

4. A removable sheet metal panel structure such as an economizer door for boiler enclosures; said structure comprising two adjoining sections; each section having reinforcing marginal rails and having an outwardly extending portion along the margin adjoining the other section; the rounded edge between the main portion of the structure and the outwardly extending portion being squared off at the'ends by a welded-on metal deposit; said squared ofi ends being adapted to provide a substantially uninterrupted marginal supporting area for the structure in the retwo sections meet.

I BENJAMIN LABAREE.

BQB R K- gion where the on its opposite sides 

